Direct Protein Detection in Solutions of High Ionic Strength using Polyethylene Glycol‐modified AlGaN/GaN High Electron Mobility Transistors

Abstract

Herein, we proposed a simple 3‐(aminopropyl) triethoxysilane/polyethylene glycol (APTES/PEG)‐AlGaN/GaN high electron mobility transistors (HEMT) biosensor that enabled direct detection in high ionic strength solutions. Unlike previous modification strategies, the PEG‐modified on the GaN surface established a stable screening system by forming a porous biopolymer layer, which can overcome Debye shielding. In our work, the APTES/PEG modification enabled immunoglobulin G (IgG) to be easily detected in solutions with concentrations of up to 30 mM (3x) of phosphate buffered saline (PBS), indicating that the APTES/PEG modification strategy had the potential for direct detection of biomolecules in physiological solutions, which provided a new method for bio‐surface modification on GaN and advanced the practical application of AlGaN/GaN HEMT biosensors.

晶体管生物传感：界面调控策略及生物医学应用

“…的离子浓度从 10 mmol L -1 降低至 0.1 mmol L -1 时， 德拜长度从 0.3 nm 延长到 7.0 nm [30,31] . 然而，在低离子强度溶液中，生物分子的构象难以维持稳定，导致待测 靶标与生物识别元件之间的结合亲和力下降 [32,33] .…”

A salivary urea sensor based on a microsieve disposable gate AlGaN/GaN high electron mobility transistor

“…[32][33][34][35][36] The exceptional responsiveness of the highly sensitive two-dimensional electron gas (2DEG), located near the surface of the AlGaN/GaN HEMT sensor, enables effective detection of changes in surface potential. [37][38][39][40][41][42][43][44][45] Recent applications have successfully demonstrated the use of AlGaN/GaN HEMT sensors in detecting proteins (biomarkers/antigens), 37,42 ions, 43,44,46 DNA hybridization events, 47,48 and pH levels 38,40,45 within solution or serum samples. However, a challenge remains in directly and rapidly detecting biomolecules in complex physiological solutions like saliva or blood.…”